Slab reenforcement



July 9, 1929. w. E. WHITE SLAB REENFORCEMENT Filed Feb. 2, 1928 patented July 9, 1929 UNITED STATES 1,720,193 PATENT OFFICE.

WILLIAM E. WHITE, OF CHICAGO, ILLINOIS, ASSIGNOR TO KALMAN STEEL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

SLAB REENFORCEMENT.

Application filed February 2, 1928. Serial No. 251,295.

My invention relates to concrete reenforcement and particularly to novel means for reentorcing precast slabs.

It is essential, at the junction of roadways with tracks or railroads and street cars, that the roadway adjacent to and between the tracks be formed other than in situ and then positioned in the desired final location. To this end it has been customary to mold suitable slabs of concrete either in the shop or adjacent to the track and move them into position when suitably seasoned. However, such slabs due to their position are subjected to the most intense and concentrated strains and blows due to the impact of heavy truck wheels at a point adjacent to the rails where I a substantial separation or gap must be provided. Furthermore, due to the conditions of support of the slabs on ties a considerable span is sometimes necessary and the resistance to bending must be taken up by reenforcement within the slabs.

These necessities have required the provision of a relatively large area of reenforcement within the concrete, but difiiculty has been experienced in insuring the placing of such reenforcement in proper position to withstand the expected loads, this difficulty arising out or the lack of a mat that could not be properly positioned n the slab mold. Such mats have been made up by welding the joints of the reentorcing elements, but due to the bulk of such mats, handling and shipping has been difficult and expensive.

An object of my invention is to provide means whereby a reenforcing mat may be built up by common workmen in the field without possibility of error either in selection. or spacing of the elements, or in distribution of the reent'orcing areas relative to the precast mass of concrete within which the reenforcement is imbedded. To accomplish this result I provide a plurality of duplicate, reversible structural shapes with identical upper and lower chords and right angularly extending struts or shear members. Such elements are equally effective in either of two positions and the workman cannot combine the units with unequal distribution of metal.

To insure proper association and spacing of the elements, I provide square holes through the web thereof and utilize a locking plate or key having notched margins, the plate being of such size that it may be promgs of a plurality of reenforcing elements, then rotated into such position that the notches register with the webs at the sides of the holes, thus acting as an accurate template for lateral spacing. The key also acts when in position to insure stability against relative longitudinal separation of the elements and in another position insures against relative vertical separation.

The invention will be more readily understood by reference to the accompanying drawings, in which Fig. 1 is an elevation of a mat or combination of reenforcing elements, the concrete slab within which it is imbedded being shown in section;

Fig. 2 is a sectional view on the line 22 of Fig. 1, and

Fig. 3 is a fragmentary perspective view showing a plurality of interlocked reenforclng elements in proper position to receive the concrete therearound.

The mat or combination of elements conslsts of a plurality of reenforcing units, together with two or more templates or interlocking keys.

The elements are preferably in the form of rolled shapes, having continuous chords 10, 11 of bulbous form and webs which are cut away at exactly spaced intervals, leaving the right angularly extending strut or shear members 12. The chord members 10, 11 are preferably of duplicate cross sectional area and as the struts extend at right angles therefrom, the elements are equally effective in which ever of two positions they are installed. The holes 13 that are punched in the webs are preferably of exactly square outline; that is, their vertical and horizontal dimensions'are the same. This accomplishes the result of providing the right angle struts and also providing for the simple means of assembly which I will now explain.

To insure proper spacing of the elements, I provide a template or interlocking key plate 14, having notches 15, 16 in its two side margins, the spacing of the notches corresponding to the desired spacing of the reenforcing elements. The transverse distance between the bottoms of the notches 15, 16 is substantially equal to the lateral space between adjacent struts 12; whereas the total width of the template is less than the diagonal distance across the opening 13, so that the template jected through the square registering openmay be inserted in registered openings of a plurality of adjacent elements, then rotated into a position such as that shown at the left in Fig. 3. When in this position the elements are properly laterally spaced and positively prevented from relative longitudinal movement. This, however, does not insure rigidity as to vertical position and therefore a second template such as indicated at the right in Fig. 3 is inserted in a similar man ner and then swung into a vertical position. Thus the combined elements are rigidly and firmly interlocked against movement in all directions and the mat may be placed in a mold with assurance that the reenforcement will be properly placed without the requirement for the exercise of any skill by the workman.

' The precise form and arrangements of the parts is not essential in order to secure desired results and therefore I do not wish to be limited except as indicated in the appended claims.

I claim:

1. In'combination, a plurality of duplicate reenforcing elements each element consisting of a. metal section having a web and continuous flanges, the Web being punched out at evenly spaced intervals to provide square 7 apertures there through, and an interlocking plate adapted to be projected through the registering openings in a plurality of adjacent elements and interlocking with the web of said elements adjacent to the openings in order to space said elements laterally and to hold the same against longitudinal shifting.

2. In combination, a plurality of duplicate reenforcing elements each element consisting of ametal section having a web and continuous flanges, the web-being punched out at evenly spaced intervals to provide square apertures there through, and an interlocking plate adapted to be projected through the registering openings in a plurality of adjacent elements and interlocking with the web of said elements adjacent to the openings in order to space said elements laterally and to hold the same against longitudinal shifting, and another substantially duplicate interlocking plate adapted to be similarly installed in another set of registering openings to hold said elements against relative vertical shifting.

' 3. In combination, a plurality of duplicate reenforcing elements each element consist ing of a length of metal having a web and continuous flange-like margins, the web being punched out at spaced intervals in the length thereof to provide square apertures there-through, and an interlocking plate hav ing its marginal edges notched at spaced intervals adapted to be projected through the registering openings of a plurality of adjacent parallel reenforcing elements and to interlock with the Web of each of said elements adjacent to the openings in order to laterally space said parallel adjacent reenforcing elements and to hold the same against longitudinal movement.

4. A reenforcing unit for concrete slabs, comprising in combination, a plurality of adjacent, parallel, registering skeleton structures, each having parallel continuous chords and struts, thereby providing an open space therebetween, and an interlocking plate, said plate having a plurality of spaced notches in its marginal edges, and adapted to be inserted within said registering openings and ro{ tated into interlocking engagement with parallel struts to hold thestructures ins paced relation to adjacent chords during the pouring of concrete.

In testimony whereof I have aflixed my signature.

WILLIAM E. WHITE. 

